1. Field of the Invention
The present invention in general relates to a barcode scanner, in particular, to a barcode scanner capable of switching reading resolution of scanning.
2. Description of Prior Art
Barcode scanner is a sensing component matched with specific optical assembly for scanning a barcode to obtain its corresponding information. In general, a barcode scanner has a resolution upper-limit for the barcode to be scanned. During scanning, only the barcode with a resolution lower than the upper-limit can be scanned by the scanner.
High resolution has become a trend for a barcode, because it can reduce the barcode volume and save the material cost. However, the resolution of the optical lens in a barcode scanner is inversely proportional to the depth of field of the optical lens. Therefore, in a barcode scanner capable of scanning a barcode with high resolution (<4 mil), its depth of field is shorter relatively. This means that it can effectively scan the barcode only when the user puts the barcode in front of the barcode scanner within a small range or a specifically back and forth distance. On the contrary, in a barcode scanner capable of scanning a barcode with low resolution (>4 mil), its depth of field is longer relatively so, during use, it is unnecessary in some degree to consider the distance between the bar code and the barcode scanner, thereby effectively enhancing the scanning efficiency.
Therefore, in order to solve aforementioned drawbacks, company or store sometimes has to prepare two barcode scanners respectively capable of scanning the barcodes with different resolutions. The barcode scanner with low resolution is used for scanning the barcode with low resolution, while the barcode scanner with high resolution is used for scanning the barcode with high resolution. Thereby, the overall scanning efficiency is enhanced.
However, preparing two kinds of barcode scanners respectively for scanning the barcodes with different resolutions can cause company or store to pay more money to purchase additional devices, especially for large retail store, like mall, where a large amount of barcode scanners are needed. Besides, the cost of a barcode scanner with high resolution is much higher than that of a barcode scanner with low resolution, which can cost a lot of operational fee, especially for large company or store.
Accordingly, after a substantially devoted study, in cooperation with the application of relative academic principles, the inventor has finally proposed the present invention designed reasonably to possess the capability to improve the drawbacks of the prior arts significantly.